As the high tempterature and complexity of the throat environment and the polytrope during the ablation process,the carbon carbon composite material throat also show a complex process,and there are many effects of different degrees from the carbon fiber micro complexity,different technology etc.
The type and quality of the carbon fiber has a big influence to the strength and ablation properties of the carbon carbon composite material. There are many different carbon fiber,like PAN base carbon fiber,pitch base carbon fiber,and rayon base carbon fiber,and each kind of the carbon fiber can be divided into many series. The carbon carbon composite material is mainly desined according to the purpose and working environment,the main properties include strength, modulus,thermal property etc. Generally speaking,the high modulus carbon fiber is good at the ablation property,and it can provide the high thermal conductivity,high density,high carbon content and low coefficient of expansion. From the microstructure of carbon fiber,there are some micro pores and cracks inside,all this factors can influence the ablation property of the carbon carbon composite material. So it must chose the carbon fiber according to the different using and different working environment.
The structure of the perform can also influence the carbon carbon composite material ablation property and thermal shock resistance. It can influence the distribution and uniformity of carbon fiber in the C/C material. The thermal shock resistance and ablation property can be improved by different perform structure,decreasing the coefficient of expansion and increasing the isotropic degree. The fiber orientation and volume content of the C/C composite material have an apparent impact on the ablation property,more fiber content, uniform structure can increase the ablation property.
Besides from the factors above,the material density,porosity,the type of matrix carbon, degree of graphitization and the impurities content also have the influence in the carbon carbon composite material properties.